What is causing speaker crackle at low volumes?

I recently purchased an older Audio system, it has the ability to go fairly loud so when i set it up I had it turned to a lower volume(1-2 on the dial) and any bass was causing like a crackling noise similar to a blown speaker, so when i turned up the volume i expected it to get worse when in fact the crackling got less noticeable which makes me believe the speakers are fine. It happens on both speakers and on any input. Also the receiver's phono channels aren't amplifying my record player properly, I actually get more signal out of the tape channel albeit very little. Does it seem like this would be the receiver? If so is it something fixable or just give up and get a new one?